(CNN) -- Not only is disgraced cyclist Lance Armstrong no longer officially a Tour de France winner -- he's no longer an Olympic medalist either.

The International Olympic Committee has stripped Armstrong of the bronze medal he won at the 2000 Olympic Games in Sydney, Australia, an IOC spokesman said Thursday. The committee has told Armstrong to return it.

The move came in advance of a televised interview in which Armstrong is believed to acknowledge for the first time that he used prohibited performance-enhancing drugs in his career.

While talk-show host Oprah Winfrey has not released details of exactly what Armstrong said in the recorded interview, she appeared to confirm media reports Tuesday that the former seven-time Tour de France champion admits doping and lying about it.

The interview will air in two parts on Thursday and Friday nights.

In October, the International Cycling Union stripped Armstrong of his Tour de France titles.

Armstrong responded a few weeks later by tweeting a photo of himself lying on a sofa in his lounge beneath the seven framed yellow jerseys from those victories.

The International Olympic Committee said in October that it was reviewing evidence against him.

"We have written to Armstrong asking him to return the medal" and informed the U.S. Olympic Committee, IOC spokesman Mark Adams said Thursday.

The decision was made "in principle" at a meeting of the IOC executive board in December, Adams said. The committee did not act on the decision until it received confirmation from the International Cycling Union that Armstrong was not appealing that agency's decision.